86 research outputs found

    Spatial Identification Methods and Systems for RFID Tags

    Get PDF
    DisertačnĂ­ prĂĄce je zaměƙena na metody a systĂ©my pro měƙenĂ­ vzdĂĄlenosti a lokalizaci RFID tagĆŻ pracujĂ­cĂ­ch v pĂĄsmu UHF. Úvod je věnovĂĄn popisu současnĂ©ho stavu vědeckĂ©ho poznĂĄnĂ­ v oblasti RFID prostorovĂ© identifikace a stručnĂ©mu shrnutĂ­ problematiky modelovĂĄnĂ­ a nĂĄvrhu prototypĆŻ těchto systĂ©mĆŻ. Po specifikaci cĂ­lĆŻ disertace pokračuje prĂĄce popisem teorie modelovĂĄnĂ­ degenerovanĂ©ho kanĂĄlu pro RFID komunikaci. Detailně jsou rozebrĂĄny metody měƙenĂ­ vzdĂĄlenosti a odhadu směru pƙíchodu signĂĄlu zaloĆŸenĂ© na zpracovĂĄnĂ­ fĂĄzovĂ© informace. Pro Ășčely lokalizace je navrĆŸeno několik scĂ©náƙƯ rozmĂ­stěnĂ­ antĂ©n. Modely degenerovanĂ©ho kanĂĄlu jsou simulovĂĄny v systĂ©mu MATLAB. VĂœznamnĂĄ část tĂ©to prĂĄce je věnovĂĄna konceptu softwarově definovanĂ©ho rĂĄdia (SDR) a specifikĆŻm jeho adaptace na UHF RFID, kterĂĄ vyuĆŸitĂ­ bÄ›ĆŸnĂœch SDR systĂ©mĆŻ značně omezujĂ­. DiskutovĂĄna je zejmĂ©na problematika prĆŻniku nosnĂ© vysĂ­lače do pƙijĂ­macĂ­ cesty a poĆŸadavky na signĂĄl lokĂĄlnĂ­ho oscilĂĄtoru pouĆŸĂ­vanĂœ pro směơovĂĄnĂ­. PrezentovĂĄny jsou tƙi vyvinutĂ© prototypy: experimentĂĄlnĂ­ dotazovač EXIN-1, měƙicĂ­ systĂ©m zaloĆŸenĂœ na platformě Ettus USRP a antĂ©nnĂ­ pƙepĂ­nacĂ­ matice pro emulaci SIMO systĂ©mu. ZĂĄvěrečnĂĄ část je zaměƙena na testovĂĄnĂ­ a zhodnocenĂ­ popisovanĂœch lokalizačnĂ­ch technik, zaloĆŸenĂœch na měƙenĂ­ komplexnĂ­ pƙenosovĂ© funkce RFID kanĂĄlu. Popisuje ĂșzkopĂĄsmovĂ©/ĆĄirokopĂĄsmovĂ© měƙenĂ­ vzdĂĄlenosti a metody odhadu směru signĂĄlu. Oba navrĆŸenĂ© scĂ©náƙe rozmĂ­stěnĂ­ antĂ©n jsou v zĂĄvěru ověƙeny lokalizačnĂ­m měƙenĂ­m v reĂĄlnĂœch podmĂ­nkĂĄch.The doctoral thesis is focused on methods and systems for ranging and localization of RFID tags operating in the UHF band. It begins with a description of the state of the art in the field of RFID positioning with short extension to the area of modeling and prototyping of such systems. After a brief specification of dissertation objectives, the thesis overviews the theory of degenerate channel modeling for RFID communication. Details are given about phase-based ranging and direction of arrival finding methods. Several antenna placement scenarios are proposed for localization purposes. The degenerate channel models are simulated in MATLAB. A significant part of the thesis is devoted to software defined radio (SDR) concept and its adaptation for UHF RFID operation, as it has its specialties which make the usage of standard SDR test equipment very disputable. Transmit carrier leakage into receiver path and requirements on local oscillator signals for mixing are discussed. The development of three experimental prototypes is also presented there: experimental interrogator EXIN-1, measurement system based on Ettus USRP platform, and antenna switching matrix for an emulation of SIMO system. The final part is focused on testing and evaluation of described positioning techniques based on complex backscatter channel transfer function measurement. Both narrowband/wideband ranging and direction of arrival methods are validated. Finally, both proposed antenna placement scenarios are evaluated with real-world measurements.

    RFID Localisation For Internet Of Things Smart Homes: A Survey

    Full text link
    The Internet of Things (IoT) enables numerous business opportunities in fields as diverse as e-health, smart cities, smart homes, among many others. The IoT incorporates multiple long-range, short-range, and personal area wireless networks and technologies into the designs of IoT applications. Localisation in indoor positioning systems plays an important role in the IoT. Location Based IoT applications range from tracking objects and people in real-time, assets management, agriculture, assisted monitoring technologies for healthcare, and smart homes, to name a few. Radio Frequency based systems for indoor positioning such as Radio Frequency Identification (RFID) is a key enabler technology for the IoT due to its costeffective, high readability rates, automatic identification and, importantly, its energy efficiency characteristic. This paper reviews the state-of-the-art RFID technologies in IoT Smart Homes applications. It presents several comparable studies of RFID based projects in smart homes and discusses the applications, techniques, algorithms, and challenges of adopting RFID technologies in IoT smart home systems.Comment: 18 pages, 2 figures, 3 table

    XRLoc: Accurate UWB Localization for XR Systems

    Full text link
    Understanding the location of ultra-wideband (UWB) tag-attached objects and people in the real world is vital to enabling a smooth cyber-physical transition. However, most UWB localization systems today require multiple anchors in the environment, which can be very cumbersome to set up. In this work, we develop XRLoc, providing an accuracy of a few centimeters in many real-world scenarios. This paper will delineate the key ideas which allow us to overcome the fundamental restrictions that plague a single anchor point from localization of a device to within an error of a few centimeters. We deploy a VR chess game using everyday objects as a demo and find that our system achieves 2.42.4 cm median accuracy and 5.35.3 cm 90th90^\mathrm{th} percentile accuracy in dynamic scenarios, performing at least 8×8\times better than state-of-art localization systems. Additionally, we implement a MAC protocol to furnish these locations for over 1010 tags at update rates of 100100 Hz, with a localization latency of ∌1\sim 1 ms

    Wireless capsule gastrointestinal endoscopy: direction of arrival estimation based localization survey

    Get PDF
    One of the significant challenges in Capsule Endoscopy (CE) is to precisely determine the pathologies location. The localization process is primarily estimated using the received signal strength from sensors in the capsule system through its movement in the gastrointestinal (GI) tract. Consequently, the wireless capsule endoscope (WCE) system requires improvement to handle the lack of the capsule instantaneous localization information and to solve the relatively low transmission data rate challenges. Furthermore, the association between the capsule’s transmitter position, capsule location, signal reduction and the capsule direction should be assessed. These measurements deliver significant information for the instantaneous capsule localization systems based on TOA (time of arrival) approach, PDOA (phase difference of arrival), RSS (received signal strength), electromagnetic, DOA (direction of arrival) and video tracking approaches are developed to locate the WCE precisely. The current article introduces the acquisition concept of the GI medical images using the endoscopy with a comprehensive description of the endoscopy system components. Capsule localization and tracking are considered to be the most important features of the WCE system, thus the current article emphasizes the most common localization systems generally, highlighting the DOA-based localization systems and discusses the required significant research challenges to be addressed

    A Framework for Automatic Behavior Generation in Multi-Function Swarms

    Get PDF
    Multi-function swarms are swarms that solve multiple tasks at once. For example, a quadcopter swarm could be tasked with exploring an area of interest while simultaneously functioning as ad-hoc relays. With this type of multi-function comes the challenge of handling potentially conflicting requirements simultaneously. Using the Quality-Diversity algorithm MAP-elites in combination with a suitable controller structure, a framework for automatic behavior generation in multi-function swarms is proposed. The framework is tested on a scenario with three simultaneous tasks: exploration, communication network creation and geolocation of RF emitters. A repertoire is evolved, consisting of a wide range of controllers, or behavior primitives, with different characteristics and trade-offs in the different tasks. This repertoire would enable the swarm to transition between behavior trade-offs online, according to the situational requirements. Furthermore, the effect of noise on the behavior characteristics in MAP-elites is investigated. A moderate number of re-evaluations is found to increase the robustness while keeping the computational requirements relatively low. A few selected controllers are examined, and the dynamics of transitioning between these controllers are explored. Finally, the study develops a methodology for analyzing the makeup of the resulting controllers. This is done through a parameter variation study where the importance of individual inputs to the swarm controllers is assessed and analyzed

    A Framework for Automatic Behavior Generation in Multi-Function Swarms

    Get PDF
    17 USC 105 interim-entered record; under review.Multi-function swarms are swarms that solve multiple tasks at once. For example, a quadcopter swarm could be tasked with exploring an area of interest while simultaneously functioning as ad-hoc relays. With this type of multi-function comes the challenge of handling potentially conflicting requirements simultaneously. Using the Quality-Diversity algorithm MAP-elites in combination with a suitable controller structure, a framework for automatic behavior generation in multi-function swarms is proposed. The framework is tested on a scenario with three simultaneous tasks: exploration, communication network creation and geolocation of Radio Frequency (RF) emitters. A repertoire is evolved, consisting of a wide range of controllers, or behavior primitives, with different characteristics and trade-offs in the different tasks. This repertoire enables the swarm to online transition between behaviors featuring different trade-offs of applications depending on the situational requirements. Furthermore, the effect of noise on the behavior characteristics in MAP-elites is investigated. A moderate number of re-evaluations is found to increase the robustness while keeping the computational requirements relatively low. A few selected controllers are examined, and the dynamics of transitioning between these controllers are explored. Finally, the study investigates the importance of individual sensor or controller inputs. This is done through ablation, where individual inputs are disabled and their impact on the performance of the swarm controllers is assessed and analyzed

    Distributed Passive Sensor Network for the Geolocation of RF Emitters

    Get PDF
    The ability to localize an RF emitter has emerged in both commercial and military technology, and is an important capability in modern cognitive radios to achieve spectral awareness. Of importance, is the accuracy of the geolocation of the RF emitter. In this thesis, we address the blind localization problem given a network of software-defined radio receivers that monitor the spectrum to determine the presence of an unknown emitter. We discuss the underlying challenges and various approaches to the geolocation problem that can be utilized. In particular, two algorithms that are used extensively in literature are investigated: time-difference of arrival, and power-difference of arrival. In the first part of the thesis, the algorithms are presented, and the error performance is characterized analytically, and then conducted through simulation. A more robust method which implements the fusion of both algorithms for an improved estimation. In the second part, we conduct a small- scale laboratory emulation of the geolocation algorithms on a network of radios to contrast the simulation results of the algorithms from the emulation results. The results provided insight to the shortcomings of each algorithm, and potential extensions for further accuracy improvement

    Communication Subsystems for Emerging Wireless Technologies

    Get PDF
    The paper describes a multi-disciplinary design of modern communication systems. The design starts with the analysis of a system in order to define requirements on its individual components. The design exploits proper models of communication channels to adapt the systems to expected transmission conditions. Input filtering of signals both in the frequency domain and in the spatial domain is ensured by a properly designed antenna. Further signal processing (amplification and further filtering) is done by electronics circuits. Finally, signal processing techniques are applied to yield information about current properties of frequency spectrum and to distribute the transmission over free subcarrier channels
    • 

    corecore